Fixed-Dose Drug Delivery Device With Helical Guidance for Multiple Doses

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Solution Overview

Problem

Existing drug delivery devices for fixed doses are complex, costly, and not user-friendly, particularly for users who struggle with dose adjustment, such as children or elderly individuals, and often require multiple components that increase waste and material usage.

Innovation Solution

A drug delivery device with a drive mechanism featuring helical and axial guiding portions, allowing for a predefined fixed dose delivery through a piston rod and drive tube mechanism that is axially movable and rotationally blocked, using a torsional drive spring for multiple doses without additional straining, and a simple activation mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a multi-dose device allows dose adjustment, then the device can deliver multiple doses, but the device complexity increases and user error risk increases

Engineering Contradiction:
Improvenumber of dosesVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The device is segmented into distinct functional components: a drive mechanism with helical guiding portions for controlled piston movement, a separate activation mechanism, and a cartridge for drug storage. This segmentation allows each component to perform its specific function independently, reducing overall complexity while enabling multiple fixed doses.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The device is pre-configured with a fixed dose amount in the cartridge and a predetermined drive mechanism setup. The helical guiding portions are pre-formed to control the piston movement path, eliminating the need for user dose adjustment actions and reducing complexity.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If a fixed dose device uses a spring mechanism for dose delivery, then the device can deliver multiple doses, but the device complexity and material usage increase

Engineering Contradiction:
Improvenumber of dosesVSAvoidmaterial usage
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The drive mechanism combines the spring mechanism with helical guiding portions integrated into a single structural assembly. This merging reduces the number of separate components and materials needed compared to having separate spring and guide structures, while still enabling multiple dose deliveries.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The helical guiding portions serve multiple functions: they guide the piston movement, provide structural support for the spring mechanism, and define the dosing path. This multi-functionality reduces the need for additional dedicated components, thereby reducing material usage.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If a device is designed for single-use disposal, then the device is simple and safe, but the cost and material waste increase

Engineering Contradiction:
ImprovesafetyVSAvoidmaterial waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The device transitions from a static single-use design to a dynamic reusable design where the drive mechanism can be reset and activated multiple times. The spring mechanism and helical guiding portions enable the piston to be repositioned and reused, changing the device from disposable to reusable while maintaining safety through controlled mechanical design.

Inventive Principle:
Principle #15Dynamics

4Adaptability or versatility

If a device requires user interaction for dose adjustment, then the device can be customized, but the ease of operation decreases for children and elderly users

Engineering Contradiction:
Improvedose customizationVSAvoidease of operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The device performs dose delivery automatically through its pre-configured spring mechanism and helical guiding portions without requiring user adjustment. The system self-regulates the dosing process, making it easy to operate for children and elderly users while still providing consistent fixed doses through its built-in mechanical control.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The device provides a user-friendly, safe, and robust solution for delivering multiple fixed doses with reduced complexity and waste, requiring minimal user interaction and ensuring consistent dose delivery.

Implementation Method 1

using a torsional drive spring for multiple doses without additional straining

Methodology Applied
Scientific EffectTorsional spring: Torsion Spring

Implementation Method 2

drive mechanism with helical and axial guiding portions

Methodology Applied
Scientific EffectHelical mechanism: Screw

Data Source

PatentEP4076594B1Drug delivery device for delivering a predefined fixed dose
Publication Date: 2025.07.09 NOVO NORDISK AS
  • EP4076594B1 patent drawingFigure 1A
  • EP4076594B1 patent drawingFigure 1B~1C
  • EP4076594B1 patent drawingFigure 1D~1F

AI summary

A drug delivery device (100, 200) for delivering a fixed dose, wherein the drug delivery device comprises: a housing assembly, a drug reservoir with a piston and a drive mechanism. The drive mechanism comprises a piston rod (109, 209) for advancing the piston to expel a drug, and a drive tube (180, 280), wherein the drive mechanism is adapted to deliver the predefined fixed dose in response to activation. The drug delivery device further comprises an activation mechanism for activating the drive mechanism, in response to moving the drive tube in an axial direction. The housing assembly comprises a guide structure for guiding the drive tube during activation and delivery of a dose, wherein the guide structure comprises an axial portion (156, 256) providing a sliding surface for guiding the drive tube during activation, and for providing a rotational stop defining an end of dose, and a helical portion (157, 257) providing a sliding surface adapted for guiding the drive tube (180, 280) during dosing. The drive tube (180, 280) comprises a guide structure comprising an axial portion (182, 282) adapted for slidably engaging the axial portion of the housing assembly for activation, and a helical portion (189, 289) for slidably engaging the helical portion of the housing assembly during dosing during dosing.